1. Field of the Invention
The present invention relates generally to devices and methods for the treatment of female urinary incontinence, and more particularly, to a guide to be used in conjunction with such devices and methods.
2. Background Discussion
Women account for more than 11 million of incontinence cases. Moreover, a majority of women with incontinence suffer from stress urinary incontinence (SUI). Women with SUI involuntarily lose urine during normal daily activities and movements, such as laughing, coughing, sneezing and regular exercise.
SUI may be caused by a functional defect of the tissue or ligaments connecting the vaginal wall with the pelvic muscles and pubic bone. Common causes include repetitive straining of the pelvic muscles, childbirth, loss of pelvic muscle tone, and estrogen loss. Such a defect results in an improperly functioning urethra. Unlike other types of incontinence, SUI is not a problem of the bladder.
Normally, the urethra, when properly supported by strong pelvic floor muscles and healthy connective tissue, maintains a tight seal to prevent involuntary loss of urine. When a woman suffers from the most common form of SUI, however, weakened muscle and pelvic tissues are unable to adequately support the urethra in its correct position. As a result, during normal movements when pressure is exerted on the bladder from the diaphragm, the urethra cannot retain its seal, permitting urine to escape. Because SUI is both embarrassing and unpredictable, many women with SUI avoid an active lifestyle and shy away from social situations.
One device and method for treating female urinary stress incontinence is described in detail in U.S. Pat. No. 5,899,909, which is incorporated herein by reference in its entirety. This patent discloses a surgical instrument comprising a shank having a handle at one end and connecting means at the other end to receive, one at a time, two curved needle-like elements which are connected at one end to one end of a mesh intended to be implanted into the body. In practice, the mesh is passed into the body via the vagina first at one end and then at the other end, at one side and the other, respectively, of the urethra to form a loop around the urethra, located between the urethra and vaginal wall. The mesh is extended over the pubis and through the abdominal wall and is tightened. The mesh ends are cut at the abdominal wall, and the mesh is left implanted in the body. This trans-vaginal procedure is exemplified by the TVT product sold by the Gynecare franchise of Ethicon Inc., a Johnson & Johnson Company, of Somerville, N.J., USA. In this procedure two 5 mm needles pass a PROLENE mesh trans-vaginally and through the abdomen to create a tension-free support around the mid urethra.
Sub-urethral slings have also been place by a different approach, wherein a needle is passed first though the abdominal wall, along the same path as described above, and eventually exiting through the vaginal incision. The tape is then coupled to the needle in some manner, and pulled back through the body from the vaginal incision and out through the abdominal incision. The chosen approach, vaginal or abdominal, will often depend on the preferences of the surgeon.
Yet another approach for implanting a sub-urethral sling has also been recently developed, wherein the implanted sling extends from beneath the urethra, and out through the obturator hole on either side. This “transobturator” procedure may involve inserting an appropriately configured needle from a vaginal incision and subsequently out through the obturator hole, or vice versa. The former technique (an “inside-out” approach) is described in further detail below. With these techniques, it has been found to be desirable to provide some sort of guide element to facilitate the path of the needle and to ensure that the needle does not nick or otherwise injure organs or nerves that are in the vicinity of the passageway of the needle. To this end, known guide elements have consisted simply of a small stainless steel tube, a portion of which has been removed to leave a straight, but C-shaped element. Such guide elements have proven less than optimal, however, as they are difficult to maintain in place without slipping, and don't provide protection against over-insertion which can lead to damage to surrounding tissues and organs. The present invention provides an improved guide device that can be used in conjunction with a transobturator approach for placing a sub-urethral sling.